CN107575037A - The optimal steel using amount design method of steel-encasing strengthening beams of concrete - Google Patents
The optimal steel using amount design method of steel-encasing strengthening beams of concrete Download PDFInfo
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- CN107575037A CN107575037A CN201710827581.XA CN201710827581A CN107575037A CN 107575037 A CN107575037 A CN 107575037A CN 201710827581 A CN201710827581 A CN 201710827581A CN 107575037 A CN107575037 A CN 107575037A
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 58
- 239000010959 steel Substances 0.000 title claims abstract description 58
- 238000013461 design Methods 0.000 title claims abstract description 17
- 238000005728 strengthening Methods 0.000 title claims abstract description 14
- 238000000034 method Methods 0.000 title claims abstract description 13
- 230000000694 effects Effects 0.000 claims abstract description 19
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 13
- 238000007596 consolidation process Methods 0.000 claims abstract description 10
- 238000009795 derivation Methods 0.000 claims abstract description 5
- 238000005452 bending Methods 0.000 claims description 6
- 229910001294 Reinforcing steel Inorganic materials 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims 1
- 230000002787 reinforcement Effects 0.000 abstract description 16
- 238000010276 construction Methods 0.000 abstract description 6
- 238000004364 calculation method Methods 0.000 abstract description 5
- 239000000463 material Substances 0.000 abstract description 5
- 206010010219 Compulsions Diseases 0.000 abstract description 4
- 230000007812 deficiency Effects 0.000 abstract description 3
- 239000002699 waste material Substances 0.000 abstract description 2
- 230000006835 compression Effects 0.000 description 4
- 238000007906 compression Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 235000013399 edible fruits Nutrition 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000012886 linear function Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012946 outsourcing Methods 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
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Abstract
The invention discloses the optimal steel using amount design method of steel-encasing strengthening beams of concrete, step are as follows：Calculate increased longitudinal shaped steel area Aa required for the beams of concrete after load increase；According to Aa, the model of the angle steel and the batten plate accordingly is selected；Calculate effect of distance factor beta between the two adjacent batten platesbp；Establish the functional relation for the consolidation effect that the beams of concrete unit steel using amount is obtained；Simultaneously derivation is simplified to the functional relation, draws the batten plate spacing optimum value.Nationality of the present invention is drawn by calculation reinforces optimal steel using amount, reinforcing process is avoided to waste steel, so that batten plate spacing arrangement more science, economy, rationally, overcome the deficiencies in the prior art, on the premise of intensity requirement and state compulsion standard is met, the usage amount of reinforcement material is reduced to greatest extent, reduces construction cost.
Description
Technical field
The present invention relates to concrete beam strengthening technical field, and more particularly to steel-encasing strengthening beams of concrete is optimal uses steel
Measure design method.
Background technology
Reinforced beam is a kind of more common structural strengthening method by steel-encasing strengthening.In the prior art,
During using steel-encasing strengthening reinforced beam, to reinforcing used by longitudinal shaped steel section choose generally according to designer
Member's experience is chosen, and after selecting section, designer, which calculates, to be met requirement for bearing capacity and then select horizontal batten plate according to construction
Size and spacing, do not consider typically to reinforce optimal steel using amount or most economical steel using amount.
And current specifications《Concrete structure reinforcement design specification》Also related content is not carried out among (GB 50367)
Regulation.
This is resulted in actual applications, and actual person can roll up outsourcing reinforcing bar to pursue fastening strength, make
Into the waste of steel.
Therefore, it is necessary to be improved to the steel-encasing strengthening method of existing reinforced beam, meeting that intensity will
On the premise of state compulsion standard of summing, the usage amount of reinforcement material is reduced to greatest extent, reduces construction cost.
The content of the invention
In view of the drawbacks described above of prior art, the present invention provides the optimal steel using amount of steel-encasing strengthening beams of concrete and set
Meter method, the first purpose of realization is overcome the deficiencies in the prior art, is meeting the premise of intensity requirement and state compulsion standard
Under, the usage amount of reinforcement material is reduced to greatest extent, reduces construction cost.
To achieve the above object, the invention discloses the optimal steel using amount design method of steel-encasing strengthening beams of concrete, institute
Stating beams of concrete includes being longitudinally disposed at angle steel on described four ribs of beams of concrete, and along the beams of concrete length side
To some batten plates that are uniform, and being arranged between the two adjacent angle steel.
When carrying out steel-encasing strengthening, reinforcement material includes longitudinal direction and is attached to the beams of concrete beams of concrete
Angle steel on four ribs, and it is uniform along the beams of concrete length direction, and be arranged between the two adjacent angle steel
Some batten plates (also referred to as lacing).
The step of design method, is as follows：
A. increased longitudinal shaped steel area Aa, formula required for the beams of concrete are after calculating load increase：
Mu=α1fcbxa(h0-xa/2)+f'yA's(h0-a's)+f'aA'a(h0-a'a),
The formula is technology customary in the art, is documented in current specifications《Concrete structure reinforcement design rule
Model》Among (GB 50367), wherein：
MuTo reinforce the anti-bending bearing capacity of the back rest；
α1：The coefficient related to strength grade of concrete；
fc：Concrete axial compressive strength design load；
b：Beams of concrete cross-sectional width；
xa：Beams of concrete section depth of compressive zone；
h0：Beams of concrete effective depth of section；
f'y：Beams of concrete compressive region reinforcing bar compression strength design load；
A's：Beams of concrete compressive region area of reinforcement；
a′s：Beams of concrete compressive region longitudinal reinforcement Resultant force to section compression area edge distance；
f'a：Longitudinal reinforcement shaped steel compression strength design load；
A'a：Compressive region longitudinal reinforcement shaped steel area of section；
a′a：Compressive region longitudinal reinforcement shaped steel Resultant force to section compression area edge distance.
B. according to required increased longitudinal shaped steel area Aa, select the corresponding angle steel and the batten plate
Model；
For the beams of concrete when beam is anti-bend reinforced, the angle steel specification size set along its length needs basis to add
Gu the bearing capacity improved needed for determines, is arranged on the beams of concrete side, some described between the two adjacent angle steel
Batten plate is directly chosen generally according to construction.
Selection for the angle steel and the batten plate is prior art, and its type selecting needs to meet《Concrete structure adds
Gu design specification》Required accordingly in (GB 50367).
According to《Concrete structure reinforcement design specification》Respective formula calculates the bearing capacity of beam in (GB 50367), according to
Mu=α1fcbxa(h0-xa/2)+f'yA's(h0-a's)+f'aA'a(h0-a'a) calculate load increase the back rest required for it is increased
Longitudinal shaped steel area Aa, MuTo reinforce the anti-bending bearing capacity of the back rest.
Then according to AaThe corresponding angle steel is selected, and the specification of the batten plate generally matches with angle steel specification, selects
The batten plate of respective cross-section product.
C. effect of distance factor beta between the two adjacent batten plates of calculatingbp, formula is：
Mu1=βbpMu,
Wherein, Mu1To consider the actual reinforcing bearing capacity after batten plate effect of distance；
The anti-bending bearing capacity of beams of concrete linearly reduces substantially with the increase of batten plate spacing, is mixed to Strengthening by Steel-Packing
When solidifying native beam anti-bending bearing capacity is calculated, batten plate effect of distance factor beta is considered asbp, βbpBatten plate spacing can be regarded as
Linear function, calculation formula βbp=Ax+B, wherein variable x represent batten plate spacing (mm), and A, B are constant.
D. the functional relation for the consolidation effect that the beams of concrete unit steel using amount is obtained is established, formula is
Wherein, T represents the reinforcing steel using amount coefficient in the beams of concrete section,
K represents the beams of concrete bearing power increase coefficient,
Mu0The ultimate bearing capacity of beams of concrete before reinforcing is represented,
βbp=Ax+B, variable x represent batten plate spacing (mm), and A, B are constant,
AaRepresent angle cross section product, A used in reinforcingLBeams of concrete sectional area is represented,
AbpThe sectional area of laterally single branch hoop batten plate is represented,
The relative steel using amount of batten plate is represented, i.e., batten plate sectional area is with mixing in unit length
The ratio of solidifying native beam section product；
Then the reinforcing steel using amount coefficient T in beams of concrete section and bearing power increase COEFFICIENT K can be represented with equation below：
Wherein, AaRepresent angle cross section product, A used in reinforcingLRepresent beams of concrete sectional area, Section 1 Aa/ALThat is angle steel
With respect to steel using amount；AbpRepresent the sectional area of laterally single branch hoop batten plate, Section 2The relative steel using amount of batten plate is represented, i.e.,
The ratio of batten plate sectional area and beams of concrete sectional area in unit length.Bearing power increase COEFFICIENT K represents that reinforcing the back rest limit holds
Carry the percentage that power improves, Mu0Represent the ultimate bearing capacity of beams of concrete before reinforcing.
Due to Mu0And MuIt is the amount unrelated with x, sees to regard constant as, then K/T can represents that unit steel using amount is obtained
The consolidation effect obtained, i.e. the functional relation for the consolidation effect that the beams of concrete unit steel using amount is obtained：
E. functional relation (1) derivation of the consolidation effect obtained to the beams of concrete unit steel using amount,
Ask for the extreme value of x during K/T ' (x)=0, as described batten plate spacing optimum value.
When x is bigger, expression batten plate spacing is bigger, then steel using amount is fewer, but consolidation effect is poorer；When x is smaller, represent
Batten plate spacing is smaller, then steel using amount is bigger, and consolidation effect is also better.Imitated in order that obtaining best reinforcing with minimum steel
Fruit, to function K/T (x) derivations, calculated to simplify, the constant in function is replaced with tetra- constant parameters of a, b, c, d, is reduced to：
Obtained after derivation：；
As K/T ' (x)=0, batten plate spacing during x value, as optimal steel using amount can be tried to achieve.
Beneficial effects of the present invention：
Nationality of the present invention is drawn by calculation reinforces optimal steel using amount, avoids reinforcing process from wasting steel so that between batten plate
Away from arrangement more science, economy, reasonable, overcome the deficiencies in the prior art, before intensity requirement and state compulsion standard is met
Put, reduce the usage amount of reinforcement material to greatest extent, reduce construction cost.
Design, concrete structure and the caused technique effect of the present invention are described further below with reference to accompanying drawing, with
It is fully understood from the purpose of the present invention, feature and effect.
Brief description of the drawings
Fig. 1 shows the structural representation of one embodiment of the invention；
Fig. 2 shows that figure of the present invention removes the sectional view of middle Section A-A
Wherein, 1, pillar, 2, need reinforcement, 3, angle steel, 4, batten plate.
Embodiment
Embodiment
As depicted in figs. 1 and 2, a beam to need reinforcement, cross section size are 400mm × 800mm, C40 coagulations
Soil, protective layer thickness 35mm, beam levels reinforcing bar is 5C20.Need to improve anti-bending bearing capacity 50% after load increase.According to
Proper calculation selects the ∟ 125 × 80 × 7 of angle steel 4, and batten plate is -80 × 8, Q235, then Aa/AL=0.01762, Abp/AL=
0.002.A=-0.0001151, B=0.9892 in batten plate effect of distance coefficient calculating formula.
Then
As K/T ' (x)=0, x=461.78mm can be tried to achieve.Understand when batten plate spacing is 461.78mm, steel using amount
Most economical, the consolidation effect that unit steel using amount obtains is maximum.
According to《Concrete structure reinforcement design specification》(GB50367-2013) regulation batten plate spacing cannot be greater than in
500mm, result of calculation have also accomplished the purpose of the optimal batten plate spacing of selection while detailing requiments are met, are very reasonable
With it is effective.
Preferred embodiment of the invention described in detail above.It should be appreciated that one of ordinary skill in the art without
Creative work can is needed to make many modifications and variations according to the design of the present invention.Therefore, all technologies in the art
Personnel can be obtained by logical analysis, reasoning, or a limited experiment on the basis of existing technology under this invention's idea
Technical scheme, all should be in the protection domain being defined in the patent claims.
Claims (1)
1. the optimal steel using amount design method of steel-encasing strengthening beams of concrete, the beams of concrete includes being longitudinally disposed at described mix
The angle steel on native four ribs of beam is coagulated, and it is uniform along the beams of concrete length direction, and it is arranged at the two adjacent angle steel
Between some batten plates；Step is as follows：
A. increased longitudinal shaped steel area Aa, formula required for the beams of concrete are after calculating load increase：
Mu=α1fcbxa(h0-xa/2)+f′yA′s(h0-a's)+f′aA'a(h0-a'a),
Wherein, MuTo reinforce the anti-bending bearing capacity of the back rest；
B. according to required increased longitudinal shaped steel area Aa, the model of the angle steel and the batten plate accordingly is selected；
C. effect of distance factor beta between the two adjacent batten plates of calculatingbp, formula is：
Mu1=βbpMu,
Wherein, Mu1To consider the actual reinforcing bearing capacity after batten plate effect of distance；
D. the functional relation for the consolidation effect that the beams of concrete unit steel using amount is obtained is established, formula is
Wherein, T represents the reinforcing steel using amount coefficient in the beams of concrete section,
K represents the beams of concrete bearing power increase coefficient,
Mu0The ultimate bearing capacity of beams of concrete before reinforcing is represented,
βbp=Ax+B, variable x represent batten plate spacing (mm), and A, B are constant,
AaRepresent angle cross section product, A used in reinforcingLBeams of concrete sectional area is represented,
AbpThe sectional area of laterally single branch hoop batten plate is represented,
Represent the relative steel using amount of batten plate, i.e., the ratio of batten plate sectional area and beams of concrete sectional area in unit length
Value；
E. functional relation (1) derivation of the consolidation effect obtained to the beams of concrete unit steel using amount, asks for K/T ' (x)
X extreme value when=0, as described batten plate spacing optimum value.
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| CN201710827581.XA CN107575037B (en) | 2017-09-14 | 2017-09-14 | The optimal steel using amount design method of steel-encasing strengthening beams of concrete |
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| CN201710827581.XA CN107575037B (en) | 2017-09-14 | 2017-09-14 | The optimal steel using amount design method of steel-encasing strengthening beams of concrete |
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| CN107575037B CN107575037B (en) | 2019-07-16 |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1401873A (en) * | 2002-09-05 | 2003-03-12 | 杜旌 | Method for pre-stressed reinforcing concrete compression member |
| JP2006063608A (en) * | 2004-08-26 | 2006-03-09 | East Japan Railway Co | Seismic reinforcement structure of concrete structure and its construction method |
| CN202788024U (en) * | 2012-09-27 | 2013-03-13 | 贵阳铝镁设计研究院有限公司 | High-rigidity concrete beam structure |
| CN102979320A (en) * | 2012-12-29 | 2013-03-20 | 上海市建筑科学研究院(集团)有限公司 | Method for reinforcing severely vibrated and damaged reinforced concrete frame structure by coating steel jacket outside |
| CN106120574A (en) * | 2016-07-07 | 2016-11-16 | 西安公路研究院 | The prestressing without bondn of concrete box girder and steel reinforced concrete composite reinforcement method for designing |
| CN205935737U (en) * | 2016-05-21 | 2017-02-08 | 叶长青 | Reinforcing structure of concrete beam |
-
2017
- 2017-09-14 CN CN201710827581.XA patent/CN107575037B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1401873A (en) * | 2002-09-05 | 2003-03-12 | 杜旌 | Method for pre-stressed reinforcing concrete compression member |
| JP2006063608A (en) * | 2004-08-26 | 2006-03-09 | East Japan Railway Co | Seismic reinforcement structure of concrete structure and its construction method |
| CN202788024U (en) * | 2012-09-27 | 2013-03-13 | 贵阳铝镁设计研究院有限公司 | High-rigidity concrete beam structure |
| CN102979320A (en) * | 2012-12-29 | 2013-03-20 | 上海市建筑科学研究院(集团)有限公司 | Method for reinforcing severely vibrated and damaged reinforced concrete frame structure by coating steel jacket outside |
| CN205935737U (en) * | 2016-05-21 | 2017-02-08 | 叶长青 | Reinforcing structure of concrete beam |
| CN106120574A (en) * | 2016-07-07 | 2016-11-16 | 西安公路研究院 | The prestressing without bondn of concrete box girder and steel reinforced concrete composite reinforcement method for designing |
Non-Patent Citations (1)
| Title |
|---|
| 陈轩: "外包钢加固钢筋混凝土梁承载能力研究", 《中国优秀硕士论文全文数据库》 * |
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